STRESS-INDUCED FORMATION OF HIGH-DENSITY AMORPHOUS-CARBON THIN-FILMS

Amorphous carbon films with high sp(3) content were deposited by magne tron sputtering and intense argon ion plating. Above a compressive str ess of 13 GPa a strong increase of the density of the carbon films is observed. We explain the increase of density by a stress-induced phase transition of sp(2) configured carbon to sp(3) configured carbon. Pre ferential sputtering of the sp(2) component in the carbon films plays a minor role compared to the sp(2) double right arrow sp(3) transition at high compressive stress formed during the deposition process. Tran smission electron microscopy shows evidence of graphitic regions in th e magnetron sputtered/Ar plated amorphous carbon thin films. Differenc es in the microstructure of the tetrahedral amorphous carbon (ta-C) fi lms deposited by filtered are and mass selected ion beam; and those fi lms deposited using magnetron sputtering combined with intense ion pla ting can be used to explain the different electronic and optical prope rties of both kinds of ta-C films. (C) 1997 American Institute of Phys ics.